Using non-audio data embedded in an audio signal

ABSTRACT

Embodiments included herein generally relate to using non-audio data embedded in an audio signal. More particularly, embodiments relate to using non-audio data embedded into the audio signal to control an audio configuration of a plurality of speakers and/or to measure a delay of a playback device.

TECHNICAL FIELD

Embodiments included herein generally relate to using non-audio dataembedded in an audio signal. More particularly, embodiments relate tousing non-audio data embedded into the audio signal to control an audioconfiguration of a plurality of speakers and/or to measure a delay of aplayback device.

BACKGROUND

In entertainment systems, media content may be distributed to any numberof playback devices, such as speakers and/or televisions. However, insome situations, a user may want to showcase different features ofdifferent types of playback devices and/or determine a latency of theplayback device. In the former situation, the user may have limitedaccess to activate and/or deactivate the different types of playbackdevices, such that the user may be limited in their ability to showcasethe different features of the various playback devices. In the lattersituation, each individual playback device may incur a distinct latency,such that the user must account for such latency on a device by devicebasis.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and form a partof the specification.

FIG. 1 illustrates an entertainment system with a plurality ofheterogeneous speaker devices, according to some embodiments.

FIG. 2 illustrates a flowchart for controlling one or more speakerdevices based on a bias signal, according to some embodiments.

FIG. 3 illustrates another entertainment system, according to someembodiments.

FIG. 4 illustrates a flowchart for measuring latency of a media playbackdevice, according to some embodiments.

FIG. 5 illustrates a speaker device, according to some embodiments.

FIG. 6 illustrates a media content device, according to someembodiments.

FIG. 7 illustrates an example computer system useful for implementingvarious embodiments.

In the drawings, like reference numbers generally indicate identical orsimilar elements. Additionally, generally, the left-most digit(s) of areference number identifies the drawing in which the reference numberfirst appears.

SUMMARY

Provided herein are system, apparatus, article of manufacture, methodand/or computer program product embodiments, and/or combinations andsub-combinations thereof, for using non-audio data embedded into theaudio signal to control an audio configuration of plurality of speakersand/or to measure a delay of a playback device.

In some embodiments, the present disclosure is directed to a method forcontrolling one or more speaker devices based on a bias signal. Forexample, the method may include transmitting media content having a biassignal embedded therein to each of a plurality of speakers. In someembodiments, the bias signal may indicate a current state from among aplurality of states to be activated. The method may further includeconfiguring each of the plurality of speakers with a respective statefrom among the plurality of states. The method may also includemodifying an audio configuration of one or more speakers of theplurality of speakers based on the bias signal.

In some embodiments, the present disclosure is directed to a method formeasuring a latency of a playback device. For example, the method mayinclude measuring a clocking sample from an internal clock of a mediasource. The method may also include encoding the clocking sample togenerate a first audio stream and combining the first audio stream witha second audio stream to generate a combined audio stream. The methodmay further include transmitting the combined audio stream through aplayback device. The method may also include decoding audio samplesreceived from the playback device to extract timestamps of the playbackdevice. The method may further include comparing the extracted timestamps with the clocking sample to determine a latency of the playbackdevice.

Further features and advantages of the embodiments disclosed herein, aswell as the structure and operation of various embodiments, aredescribed in details below with reference to the accompanying drawings.It is noted that this disclosure is not limited to the specificembodiments described herein. Such embodiments are presented herein forillustrative purposes only. Additional embodiments will be apparent to aperson skilled in the relevant art based on the teachings containedherein.

DETAILED DESCRIPTION OF THE INVENTION

Provided herein are system, method, computer program product and/ordevice embodiments, and/or combinations thereof, to using non-audio dataembedded into the audio signal to control an audio configuration of aplurality of speakers and/or to measure a delay of a playback device.

FIG. 1 illustrates an entertainment system for providing audio contentvia a plurality of heterogeneous speaker devices. Referring to FIG. 1,an entertainment system 100 may include a plurality of speaker devices102, e.g., speaker devices 102(1)-102(n), collectively referred to asspeakers 102, placed in any location and/or configuration within alistening environment, and a media content device 104. Each speakerdevice 102 may be wired or wireless. Although FIG. 1 illustrates twospeaker devices 102, the entertainment system 100 may include any numberof speaker devices 102, as should be understood by those of ordinaryskill in the art.

The media content device 104 may be, without limitation, a media player,television, a wireless device, a smartphone, a tablet computer, alaptop/mobile computer, a handheld computer, a server computer, anin-appliance device, Internet of Things (IoT) device, streaming mediaplayer, a game console, and/or an audio/video receiver. In someembodiments, the media content device 104 may be located in the samelistening environment as the plurality of speaker devices 102.Additionally, or alternatively, the media content device 104 may belocated remotely from the speaker devices 102. The speaker devices 102and the content device 104 may communicate via a communicationnetwork(s) 106. The communication network 106 may include any or all ofa wired and/or wireless private network, personal area network (PAN),Local-Area Network (LAN), a Wide-Area Network (WAN), or the Internet.

In some embodiments, the speaker devices 102 may be different types ofaudio devices. For example, the speaker devices 102 may be, withoutlimitation, a combination of one or more different types of speakers,such as full-range drivers, subwoofers, woofers, mid-range drivers,tweeters, sound bars, and/or coaxial drivers, to name just someexamples. It should be understood by those of ordinary skill in the artsthat each of the speakers 102 may be designed to produce sound atdifferent frequencies. For example, a tweeter may be designed to producesound at high audio frequencies, e.g., 2,000 Hz to 20,000 Hz, whereassubwoofers and woofers may be designed to produce sound at low audiofrequencies, e.g., 40 Hz up to 500 Hz. As such, each speaker 102 may bedesigned to produce different features of an audio signal, e.g.,tweeters may be designed to produce more treble, whereas woofers andsub-woofers may be designed to produce more bass and sub-bass,respectively.

In some embodiments, media content 110 may be stored on the mediacontent device 104 and transmitted to each of the speakers 102, suchthat the speakers 102 synchronously reproduce the media content 110. Toillustrate the different characters of the plurality of speakers 102,the media content 110 may be embedded with a control signal, which maycause different ones of the speakers 102 to modify its respective audioconfiguration in-real time. In some embodiments, the control signal maybe a direct current (DC) bias signal that indicates a respective statefor each speaker of the plurality of speakers 102. In some embodiments,the DC bias signal may be transmitted over two channels, e.g., a leftchannel and a right channel, of each of speaker 102. The DC bias signalmay include a plurality of states on each channel. For example, the DCbias signal may include no bias, a positive bias, or a negative bias.Thus, in some embodiments, the DC bias signal may be used to create, forexample, nine (9) different states. It should be understood by those ofordinary skill in the art that the bias signal shifts the signal of themedia content 110. It should be further understood by those of ordinaryskill in the arts that the number of states described herein is merelyan example, and that any number of states may be used in accordance withaspects of the present disclosure. For example, in some embodiments, inorder to increase the number of states, the DC bias signal may be a moregranular DC bias with more than three biases. Table I illustrates anexample table of the nine (9) different states for the speakers 102.

TABLE I Left Channel Right Chanel 0 −1 0 0 0 1 1 −1 1 0 1 1 −1 −1 −1 0−1 1

Embedding the bias signal into the media content may include masteringthe media content 110. For example, mastering the media content 110 mayinclude filtering the media content 110 using, for example, a high-passfilter to remove any inherent bias in the media content 110. Masteringthe media content 110 may further include normalizing the media content110. In some embodiments, normalizing the media content 110 may includeadjusting the media content 110 by, for example, −3 dB to ensure thatthe media content 110 has headroom to account for the bias signal.Mastering the media content 110 may also include combining thenormalized media content with the bias signal. In some embodiments, themedia content 110 may be mastered and loaded onto the media contentdevice 104. In further embodiments, the media content 110 may bemastered in in-real time by a user operating the media content device104.

The media content 110 may also include one or more transitions to allowfor the speakers 102 to seamlessly transition from one state to anotherwithout any interruptions in the media content 110. In order totransition from one state to another state, the changes in the DC biassignal may be embedded in the media content 110 at low frequencies,e.g., about 8 Hz, such that the transition(s) are sub-audible. In someembodiments, the transitions may be filtered to remove any frequenciesaudible to humans.

Each of the speakers 102 may be preloaded with a data file indicating astate for each of the speakers 102. In some embodiments, the data filemay be side-loaded into each speaker 102 and stored in a repository ofthe speaker 102. Thus, in some embodiments, the speakers 102 may beupdated with a new data file indicating the states of the speakers 102.In some embodiments, the speakers 102 may each be configured torecognize an operating state based on the DC bias signal and to changeits audio configuration in response to receiving the DC bias signalindicating which state(s) is active. In some embodiments, the speakers102 may also be configured to recognize the state of each of the otherspeakers 102. Based on recognizing the state of each of the otherspeakers 102, each individual speaker 102 may be further configured tochange its audio configuration according to which other speakers 102 areactive within the system 100. For example, when a subwoofer changes itsaudio configuration to be unmuted, it may also be aware that tweeter mayalso be unmuted, and as such, the subwoofer may changes its audioconfiguration such that the tweeter is a dominant speaker. In someembodiments, each speaker 102 may be configured to filter out the biassignal, such that the bias signal does not affect the quality of themedia content 110. In further embodiments, the speakers 102 may bechoreographed such that different ones of the speakers 102 mayillustrate its different audio characteristics at different points intime.

In some embodiments, the audio configuration may include, but is notlimited to, an output status of the speaker 102 (e.g., mute/unmuted), across-over of the speaker 102, or the like. To modify its audioconfiguration, each speaker 102 may modify one or more filter settings118(1)-118(n) in response to detecting the bias signal. For instance,the filter settings 118 of any given speaker 102 may be modified toadjust one or more audio features of the speaker 102 (bass, treble,balance, midrange, fading, etc.), a preferred sound mode (movie, music,surround decoder, direct playback, unprocessed, etc.), a movie mode(standard, sci-fi, adventure, drama, sports, etc.), a music mode(concert hall, chamber, cellar club, music video, 2 channel stereo,etc.), reproduction mode (e.g., stereo mode, surround sound mode, monomode), as well as any other audio characteristics.

FIG. 2 illustrates a flowchart for controlling one or more speakerdevices based on a bias signal. For example, in 210, a media contentdevice may transmit using, for example, a communication interface 602 ofFIG. 6, media content having a bias signal embedded therein to each of aplurality of speakers. In some embodiments, the bias signal may indicatea current state from among a plurality of states to be activated. In220, a processor of each speaker 102, for example, a processor 506 ofFIG. 5, may configure each respective speaker of the plurality ofspeakers with a respective state from among the plurality of states. In230, one or more processors, for example, the processor 506 of FIG. 5,may modify an audio configuration of one or more respective speakers ofthe plurality of speakers based on the bias signal.

FIG. 3 illustrates another entertainment system, according to someembodiments. Referring to FIG. 3, an entertainment system 300 mayinclude a playback device 302 and a media content device 304. The mediacontent device 304 may be, without limitation, a media player,television, a wireless device, a smartphone, a tablet computer, alaptop/mobile computer, a handheld computer, a server computer, anin-appliance device, streaming media player, a game console, and/or anaudio/video receiver. In some embodiments, the media content device 304may be located in the same listening environment as the playback device302. Additionally, or alternatively, the media content device 304 may belocated remotely from the playback device 302. The playback device 302and the content device 304 may communicate via a communicationnetwork(s) 306. The communication network 306 may include any or all ofa wired and/or wireless private network, personal area network (PAN),Local-Area Network (LAN), a Wide-Area Network (WAN), or the Internet.

In some embodiments, the playback device 302 may be any type of aplayback device. For example, the playback device 302 may be a speaker,a television, a wireless device, a smartphone, a tablet computer, alaptop/mobile computer, a handheld computer, a wearable, a servercomputer, a streaming media player, a game console, an audio/videoreceiver, and so forth.

In some embodiments, media content 310 may be stored on the mediacontent device 304 and transmitted through the playback device 302. Insome embodiments, the media content 110 may be combined with a secondsignal, such that the combined signal is used to measure a latency ofthe playback device 302. To generate the second signal, the mediacontent device 304 may measure a clocking sample from an internal clock.In some embodiments, the internal clock may be a high-resolution clock.In some embodiments, the content device 304 may measure the clockingsample in response to detecting a connection between the content device304 and the playback device 302. In some embodiments, the connectionbetween the content device 304 and the playback device 302 may be awired connection using, for example, a high-definition multimediainterface (HDMI) cable or an optical S/PDIF (Sony/Philips DigitalInterface) cable.

In some embodiments, the media content device 304 may encode theclocking sample using an encoder to generate an encoded audio stream.The encoded audio stream may be centered around an inaudible frequencyrange, i.e., inaudible to humans. For example, the encoded audio streammay be centered around a frequency of about 19.5 Khz, e.g., between 19Khz and 20 Khz. The clocking sample may be encoded using, for example, afrequency shift keying encoding scheme. It should be understood by thoseof ordinary skill in the that the frequency shift keying scheme ismerely one example coding scheme that may be used, and that otherencoding schemes are further contemplated in accordance with aspects ofthe present disclosure.

The media content device 304 may combine the media content 310 with theencoded audio stream to generate a global audio stream and transmit theglobal audio stream through the playback device 302. In some instances,the playback device 302 may cause an internal latency with respect tothe global audio stream. For example, the playback device 302 may causethe internal latency when normalizing a volume of the global audiostream. After the playback device 302 processes the global audio stream,the playback device 302 may return the global signal back to the mediacontent device 304. The returned signal may include audio samples, suchas pulse-code modulation (PCM) samples.

The media content device 304 may decode the audio samples received fromthe playback device using a decoder to extract timestamps of theplayback device. For example, the media content device 304 may decodethe audio samples using a decoding scheme configured to decodeinformation encoded using the frequency shift keying scheme. The mediacontent device 304 may then compare the extracted time stamps with theclocking sample to determine the latency of the playback device 302. Insome embodiments, the media content device 304 may adjust a timing ofthe media content 310 based on the latency of the playback device 302.

FIG. 4 illustrates a flowchart for measuring a latency of a playbackdevice, according to some embodiments. In 410, a processor of a mediacontent device, for example, processor 606 of FIG. 6, may measure aclocking sample from an internal clock, for example, internal clock 612of FIG. 6, of a media source. In 420, an encoder, for example, encoder604 of FIG. 6, may encode the clocking sample to generate a first audiostream, and in 430, the processor 606 may combine the first audio streamwith a second audio stream to generate a combined audio stream. In 440,a communications interface, for example, communications interface 602 ofFIG. 6, may transmit the combined audio stream through a playbackdevice. In 450, a decoder, for example, decoder 614 of FIG. 6, maydecode audio samples received from the playback device to extracttimestamps of the playback device. In 460, the processor 606 may comparethe extracted time stamps with the clocking sample to determine alatency of the playback device 460. It should be understood by those ofordinary skill in the arts that the present disclosure may also be usedto verify a complete audio path between the media content device and theplayback device.

FIG. 5 is a block diagram of an example embodiment 500 of a speakerdevice, e.g., the speakers 102 of FIG. 1. The speaker device 500 maycomprise one or more communication interfaces 502 for receiving content(e.g., the media content 110 of FIG. 1) from a content device (e.g., themedia content device 104 of FIG. 1), a decoder 504 for decoding themedia content into its separate audio components, a processor 506, aspeaker control module 518 for receiving user commands via one or morecontrols (e.g., buttons and/or a remote control interface), a powersupply 520, or more filters 528 (e.g., the filters 120), and a speakercabinet 522 to enclose components of the speaker device 500.

The communication interface(s) 502 may include one or more interfacesand hardware components for enabling communication with various otherdevices. For example, communication interface(s) 502 facilitatecommunication through one or more of the Internet, cellular networks,and wireless networks (e.g., Wi-Fi, cellular). The non-transitory,tangible computer readable memory (CRM) 508 may be used to store anynumber of functional components that are executable by the processor506. In many implementations, these functional components compriseinstructions or programs that are executable by the processors and that,when executed, specifically configure the one or more processors 506 toperform the actions attributed above to the speaker devices (e.g., thespeaker devices 102). In addition, the non-transitory, tangible computerreadable memory 508 stores data used for performing the operationsdescribed herein. In the illustrated example, the functional componentsstored in the non-transitory computer readable memory 508 include amanagement module 524, and a location module 526. In some embodiments,the location module 526 may include a global positioning system (GPS)and/or an indoor positioning system (IPS) device. Further, thenon-transitory computer readable memory 508 may store state informationand filter settings 532 corresponding to the speaker device 500.

The processor 506 may select which portion of the content will beprocessed. In some embodiments, in a stereo mode, the speaker device 500processes either the left stereophonic channel or right stereophonicchannel. In a surround sound mode, the speaker device 500 selects asignal to process from among the multiple channels. The selection of theplayback mode (e.g., stereo mode, mono mode, surround sound mode) may beperformed via the speaker control module 518. In some embodiments, thefilters 528 modify the content to determine the frequencies of thecontent that are reproduced by the speaker device 500 in accordance withthe filter settings 532. This may be done by performing crossover, phasematching, and time alignment filtering function in a digitalimplementation. In some examples, the filters 528 may include FIR or IIRfilters that implement a crossover filtering technique.

The output of the processor 506 may be a set of filtered digital audiosignals, one for each of the transducers 512. These signals may bedirected to the inputs of digital amplifiers, which generate high poweroutput signals that drive the speaker transducers 512 to produce anoptimal and/or improved reproduction of the content in concert with oneor more other speaker devices having different performance capabilitiesin accordance with the present invention.

FIG. 6 illustrates a media content device, according to someembodiments. In some embodiments, the media content device 600 maycomprise one or more communication interfaces 602 for transmittingcontent (e.g., the media content 110 of FIG. 1 and/or media content 310of FIG. 3) to a playback device (e.g., speakers 102 of FIG. 1 and/or athird-party playback device 320 of FIG. 3), an encoder 604 for encoding,for example, a clock signal, a processor 606 (e.g., a digital signalprocessor), a non-transitory computer readable memory 608 coupled to theprocessor 606, a user interface 610, an internal clock 612, and adecoder 614. The communication interface(s) 602 may include one or moreinterfaces and hardware components for enabling communication withvarious other devices. For example, communication interface(s) 602facilitate communication through one or more of the Internet, cellularnetworks, and wireless networks (e.g., Wi-Fi, cellular). Thenon-transitory, tangible computer readable memory (CRM) 608 may be usedto store the media content (e.g., media content 110 of FIG. 1 and/ormedia content 310 of FIG. 3), as well as any number of functionalcomponents that are executable by the processor 606. In manyimplementations, these functional components comprise instructions orprograms that are executable by the processor 606 and that, whenexecuted, specifically configure the one or more processors 606 toperform the actions attributed above to the media content device (e.g.,the media content 110 of FIG. 1 and/or media content 310 of FIG. 3). Inaddition, the non-transitory, tangible computer readable memory 608stores data used for performing the operations described herein. In someembodiments, the user interface module 610 may be used to, for example,modify the states of the speakers (e.g., speakers 102 of FIG. 1).

It will be appreciated by those skilled in the art that thefunctionality of the speaker devices described herein may be performedby other entertainment devices, such as a media player, television, awireless device, a smartphone, a tablet computer, a laptop/mobilecomputer, a handheld computer, a server computer, an in-appliancedevice, streaming media player, a game console, an audio/video receiver,and so forth.

Example Computer System

Various embodiments can be implemented, for example, using one or morewell-known computer systems, such as computer system 700 shown in FIG.7. Computer system 700 can be any well-known computer capable ofperforming the functions described herein, such as computers availablefrom International Business Machines, Apple, Sun, HP, Dell, Sony,Toshiba, etc.

Computer system 700 includes one or more processors (also called centralprocessing units, or CPUs), such as a processor 704. Processor 704 isconnected to a communication infrastructure or bus 706.

Computer system 700 also includes user input/output device(s) 703, suchas monitors, keyboards, pointing devices, etc., which communicate withcommunication infrastructure 706 through user input/output interface(s)702.

Computer system 700 also includes a main or primary memory 708, such asrandom access memory (RAM). Main memory 708 may include one or morelevels of cache. Main memory 708 has stored therein control logic (i.e.,computer software) and/or data.

Computer system 700 may also include one or more secondary storagedevices or memory 710. Secondary memory 710 may include, for example, ahard disk drive 712 and/or a removable storage device or drive 714.Removable storage drive 714 may be a floppy disk drive, a magnetic tapedrive, a compact disk drive, an optical storage device, tape backupdevice, and/or any other storage device/drive.

Removable storage drive 714 may interact with a removable storage unit718. Removable storage unit 718 includes a computer usable or readablestorage device having stored thereon computer software (control logic)and/or data. Removable storage unit 718 may be a floppy disk, magnetictape, compact disk, DVD, optical storage disk, and/any other computerdata storage device. Removable storage drive 714 reads from and/orwrites to removable storage unit 718 in a well-known manner.

According to an exemplary embodiment, secondary memory 710 may includeother means, instrumentalities or other approaches for allowing computerprograms and/or other instructions and/or data to be accessed bycomputer system 700. Such means, instrumentalities or other approachesmay include, for example, a removable storage unit 722 and an interface720. Examples of the removable storage unit 722 and the interface 720may include a program cartridge and cartridge interface (such as thatfound in video game devices), a removable memory chip (such as an EPROMor PROM) and associated socket, a memory stick and USB port, a memorycard and associated memory card slot, and/or any other removable storageunit and associated interface.

Computer system 700 may further include a communication or networkinterface 724. Communication interface 724 enables computer system 700to communicate and interact with any combination of remote devices,remote networks, remote entities, etc. (individually and collectivelyreferenced by reference number 728). For example, communicationinterface 724 may allow computer system 700 to communicate with remotedevices 728 over communications path 726, which may be wired and/orwireless, and which may include any combination of LANs, WANs, theInternet, etc. Control logic and/or data may be transmitted to and fromcomputer system 700 via communication path 726.

In an embodiment, a tangible apparatus or article of manufacturecomprising a tangible computer useable or readable medium having controllogic (software) stored thereon is also referred to herein as a computerprogram product or program storage device. This includes, but is notlimited to, computer system 700, main memory 708, secondary memory 710,and removable storage units 718 and 722, as well as tangible articles ofmanufacture embodying any combination of the foregoing. Such controllogic, when executed by one or more data processing devices (such ascomputer system 700), causes such data processing devices to operate asdescribed herein.

Based on the teachings contained in this disclosure, it will be apparentto persons skilled in the relevant art(s) how to make and useembodiments of this disclosure using data processing devices, computersystems and/or computer architectures other than that shown in FIG. 7.In particular, embodiments can operate with software, hardware, and/oroperating system implementations other than those described herein.

It is to be appreciated that the Detailed Description section, and notany other section, is intended to be used to interpret the claims. Othersections can set forth one or more but not all exemplary embodiments ascontemplated by the inventor(s), and thus, are not intended to limitthis disclosure or the appended claims in any way.

While this disclosure describes exemplary embodiments for exemplaryfields and applications, it should be understood that the disclosure isnot limited thereto. Other embodiments and modifications thereto arepossible, and are within the scope and spirit of this disclosure. Forexample, and without limiting the generality of this paragraph,embodiments are not limited to the software, hardware, firmware, and/orentities illustrated in the figures and/or described herein. Further,embodiments (whether or not explicitly described herein) havesignificant utility to fields and applications beyond the examplesdescribed herein.

Embodiments have been described herein with the aid of functionalbuilding blocks illustrating the implementation of specified functionsand relationships thereof. The boundaries of these functional buildingblocks have been arbitrarily defined herein for the convenience of thedescription. Alternate boundaries can be defined as long as thespecified functions and relationships (or equivalents thereof) areappropriately performed. Also, alternative embodiments can performfunctional blocks, steps, operations, methods, etc. using orderingsdifferent than those described herein.

References herein to “one embodiment,” “an embodiment,” “an exampleembodiment,” or similar phrases, indicate that the embodiment describedcan include a particular feature, structure, or characteristic, butevery embodiment can not necessarily include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it would be within the knowledge of persons skilled in therelevant art(s) to incorporate such feature, structure, orcharacteristic into other embodiments whether or not explicitlymentioned or described herein. Additionally, some embodiments can bedescribed using the expression “coupled” and “connected” along withtheir derivatives. These terms are not necessarily intended as synonymsfor each other. For example, some embodiments can be described using theterms “connected” and/or “coupled” to indicate that two or more elementsare in direct physical or electrical contact with each other. The term“coupled,” however, can also mean that two or more elements are not indirect contact with each other, but yet still co-operate or interactwith each other.

The breadth and scope of this disclosure should not be limited by any ofthe above-described exemplary embodiments, but should be defined only inaccordance with the following claims and their equivalents.

What is claimed is:
 1. A method comprising: measuring, by a mediacontent device, in response to detecting a wired connection between themedia content device and a playback device, a clocking sample from aninternal clock of the media content device that stores media content;encoding the clocking sample to generate a first audio stream;combining, by the media content device, the first audio stream with asecond audio stream to generate a combined audio stream, wherein thesecond audio stream is the media content; transmitting, by the mediacontent device, the combined audio stream through the playback device,wherein the combined audio stream includes the media content and isprocessed by the playback device; receiving, by the media contentdevice, a returned signal from the playback device, wherein the returnedsignal includes audio samples; decoding, by the media content device,the audio samples received from the playback device to extracttimestamps of the playback device; and comparing, by the media contentdevice, the extracted timestamps of the playback device with theclocking sample of the media content device to determine a latency ofthe playback device.
 2. The method of claim 1, further comprisingadjusting a timing of the second audio stream based on the latency ofthe playback device.
 3. The method of claim 1, wherein the wiredconnection comprises a high-definition multimedia interface (HDMI)connection or an optical Sony/Philips Digital Interface (S/PDIF) cable.4. The method of claim 1, wherein the playback device comprises anaudio-visual transceiver.
 5. The method of claim 1, wherein encoding theclocking sample comprises encoding the clocking sample using a frequencyshift keying scheme.
 6. The method of claim 1, wherein the first audiostream is generated at a frequency inaudible to humans.
 7. The method ofclaim 1, wherein the first audio stream is centered at a frequency ofabout 19.5 Khz.
 8. A system comprising: a memory; and a processorcoupled to the memory and configured to: measure a clocking sample froman internal clock of a media content device that stores media content inresponse to detecting a wired connection between the media contentdevice and a playback device; encode the clocking sample to generate afirst audio stream; combine the first audio stream with a second audiostream to generate a combined audio stream, wherein the second audiostream is the media content; transmit the combined audio stream throughthe playback device, wherein the combined audio stream includes themedia content and is processed by the playback device; receive, by themedia content device, a returned signal from the playback device,wherein the returned signal includes audio samples; decode, by the mediacontent device, the audio samples received from the playback device toextract timestamps of the playback device; and compare, by the mediacontent device, the extracted timestamps of the playback device with theclocking sample of the media content device to determine a latency ofthe playback device.
 9. The system of claim 8, wherein the processor isfurther configured to adjust a timing of the second audio stream basedon the latency of the playback device.
 10. The system of claim 8,wherein the wired connection comprises a high-definition multimediainterface (HDMI) connection or an optical Sony/Philips Digital Interface(S/PDIF) cable.
 11. The system of claim 8, wherein the playback devicecomprises an audio-visual transceiver.
 12. The system of claim 8,wherein, to encode the clocking sample, the processor is furtherconfigured to encode the clocking sample using a frequency shift keyingscheme.
 13. The system of claim 8, wherein the first audio stream isgenerated at a frequency inaudible to humans.
 14. A non-transitory,tangible computer-readable medium having instructions stored thereonthat, when executed by at least one computing device, cause the at leastone computing device to perform operations comprising: measuring, by amedia content device, in response to detecting a wired connectionbetween the media content device and a playback device, a clockingsample from an internal clock of the media content device; encoding theclocking sample to generate a first audio stream; combining, by themedia content device, the first audio stream with a second audio streamto generate a combined audio stream, wherein the second audio stream isthe media content; transmitting, by the media content device, thecombined audio stream through the playback device, wherein the combinedaudio stream includes the media content and is processed by the playbackdevice; receiving, by the media content device, a returned signal fromthe playback device, wherein the returned signal includes audio samples;decoding, by the media content device, the audio samples received fromthe playback device to extract timestamps of the playback device; andcomparing, by the media content device, the extracted time stamps of theplayback device with the clocking sample of the media content device todetermine a latency of the playback device.
 15. The medium of claim 14,wherein the operations further comprise adjusting a timing of the secondaudio stream based on the latency of the playback device.